Question

With which species is the Cu2+ ion isoelectronic?

Answer 1

isoelectronic species refers to the elements that have the same number of electrons.

Mg2+ is a 10 electron species.(1s2 2s2 2p6)

Its configuration is like that of Ne. Thus it is isoelectronic with any element having 10e- or we can say 8e-in its valence shell. (2s2 2p6)

Thus Mg2+ is isoelectronic with F- and Na+

(Both having configuration similar to Ne)